Vienna: World and regional powers agreed on Tuesday to try and turn Syria's shaky pause in fighting into a comprehensive cease-fire as a step toward ending the five-year war that left hundreds of thousands dead and fueled the rise of Islamic extremists.
Outlining other results, US Secretary of State John Kerry said participants set a June 1 deadline for the resumption of humanitarian aid to areas cut off from the outside world.
If land routes remain blocked, food aid will be air dropped and international pressure will be increased on those blocking such relief, he said.
Such pressure will also be applied to stop indiscriminate use of force by the Syrian military, Kerry added, without specifying what pressure the powers could apply.
But beyond such pledges the meeting did not devise any concrete ways to resolve the main problem standing in the way of peace - factional divisions. Without that, progress in ending the violence and reducing Syria's human misery can only be marginal and temporary.
Kerry said as much to reporters, declaring that to end the conflict "a variety of competing interests are going to have to be reconciled."
"Those involved in this conflict with competing agendas are going to have to prioritize peace," he said.
One key division continues to be the fate of Syrian President Bashar Assad. Going into the talks, German Foreign Minister Frank-Walter Steinmeier repeated the position held by the West and the Saudi-backed opposition that a peace agreement should outline steps leading to the end of his rule.
"This is necessary because there can be no lasting future for this country with Assad," he told reporters. "This is why we must start negotiations here in Vienna ... About what a transition government could look like."
Kerry did not directly mention Washington's public position that any comprehensive peace agreement must set a timetable for Assad's removal, saying only that "without a negotiated solution, Assad and his supporters will never end the war."
And he questioned suggestions that Assad was immune from international pressure to agree to a settlement. Any such conclusion by the Syrian leader is "without any foundation whatsoever, and it's very dangerous."
In a nod to Moscow, Assad's key international backer, Kerry said Russia "has made it very clear" that Assad has signed on to commitments that include participation in peace talks, constitutional change and elections.
"But he has yet to live up to the first one, which is to participate fully in the Geneva talks on a political transition," he said.
The diplomats also called on all parties to dissociate themselves from the Islamic State and the al Qaeda affiliate, known as the Nusra Front, Kerry said.